Broadcast channel group selector system



pmll y M36., c. A. RACKEY @359235 BROADCAST CHANNEL`GROUP SELECTOR SYSTEM Filed March 29, 1932 2 Sheets-Sheet l Y INVENTOR m CHESTER ARACKEY BY w v Q AWORNEY I c. A. RACKEY BROADCAST CHANNEL GROUP SELECTOR SYSTEM Filed March 29, 1932 2 Sheets-Sheet 2 lNVEN'Il'OR CHESTER A. RACKEY Patented Apr. 7, 1936 UNITED ST Chester A.. Rackey, Long Island City, N. Y., assignor to Radio Corporation of America, a. corporation oi Delaware Application March 29, 1932, Serial No. 601,726

9 Claims.

This invention relates to a method of and means for operating or controlling with minimum apparatus and effort signal channels or groups of channels interconnecting a signal source and a pointat which the signal is utilized. Control may be accomplished in accordance with this present invention at the source or at the point of utilization.

As is known to the reader, broadcasting systems in use at the present time comprise one or more transmitters linked by wire transmission lines and numerous studios which are also connected by wire lines to each other and to the several broadcasting stations. The studios in turn may be, and usually are, connected with a great number of program sources, as, for eX- ample, theaters, churches, etc. In other words, any other point at which a program of interest might originate. These points that is, the studios program source, and transmitters are interconnected by separate wire channels, or in many cases by way of existing telephone lines.

In operation the signal sources must be readily connected to one or a plurality of studios at will. Provision must be made whereby the studios may be connected over a channel or a group of channels with one or a group of transmitting stations at will. All of these connections 3 must be made with a minimum effort and apparatus. In arrangements of this nature known heretofore a complicated switching system and a great number of channels have been necessary in order that the desired program originating at any one of a plurality of sources maybe connected with a given transmitter or group oi transmitters at the desired time without interfering with other programs which might be going out on the channels prior to the broadcasting of the program in question. The primary object of this present invention is to provide a set up circuit by means of which pre-selector switches or keys may be set in advance to complete circuits in response to the closing of a master control switch, which circuits in turn insure the closing of a channel, or a plurality of channels, or groups of channels, and no others between a program source and the studio, or plurality of studios, or groups of studios, or between said source and a number of broadcasting stations, or between studios and broadcasting stations. In other words, the present invention provides a method and means whereby one point may be with ease connected u over transmission lines to a predetermined point or plurality of predetermined points, or a group of points.

While the invention has been described and illustrated with reference to its application to a chain broadcasting system, it will be understood that such description and illustration is not intended to limit the scope of the invention since, obviously, the pre-selector system of the invention may be used to control stage lights in a theater, or curtains, or to control calling systems without departing from the spirit and scope ol the invention as set forth in the claims appended hereto. In describing the invention, however, the control system will be shown to be connected with a broadcasting system or chain of the type in present use throughout the United States today.

Briefly, the channels or transmission lines, or groups of lines, are completed from one point to another through circuits including contacts associated with actuating relays, each of which includes a circuit adapted to be completed through an energizing source by way of keys which, in turn, are operatively associated with a master control circuit including pre-selector set-up keys, a relay associated with each of the last named keys, that is, the pre-selector keys, and a master combination set-up key. The pre-selector keys associated with the relays in the master control circuit may be closed at some time before it is actually desired to complete the channel or channels between the source and the point or several points. When the master combination set-up key is closed the channel completing relay circuits are energized to close a circuit through the channel or several channels associated with the relays, the circuits of which are closed by the relays associated with the pre-selector keys. Simultaneously with the closing of the channel or channels by the actuating relays, a holding circuit for the actuating relay is closed so that the channel remains closed even though the circuit closed by the pre-selector key associated with the particular channel relay is broken. A master release key, normally closed, is in circuit with the control circuit. Opening of this master release key breaks the circuit through the channel control relays in a manner which will appear more in detail hereinafter. Generally, in operation, a new set of channels to be completed is prepared by closing the pre-selector keys associated therewith while the old group of channels is in operation. Then, when it is desired to disconnect the old group of channels and place in operation the new groupof channels, all that is necessary is to 2 Cil open the master release key and close the master combination set-up key.

The particular pre-selector keys which were closed to connect the aforesaid channels, may be opened without opening the channels by operating the master release key and a new group of pre-selector keys closed so that at the desired time closing of the master combination set-up key will operate the set-up keys to complete the new channel or group of channels. A signal lamp is associated with each pre-selector key and with the master control circuit in such a manner that it is energized when the pre-selector or pre-set key has been closed, thereby indicating to the operator which channel or group of channels is to be closed.

The novel features of my invention have been pointed out with particularity in the claims appended hereto.

The nature of the invention and the mode of operation thereof will be better understood from the following detailed description thereof and therefrom when read in connection with the attached drawings throughout which like reference characters indicate like parts, and in which:

Figure l shows the details of the present selector system applied to a single source of signals which is to be connected to a plurality of channels simultaneously; while Figure 2 shows diagrammatically the selector system of Figure l applied to a larger number of signal sources to be connected to one or more of a larger number of channels.

Referring to the drawings, S indicates a source of program which it is desired to connect to one or more of the several channels I, 2, 3, N etc. The channels I, 2, 3, etc., are adapted to be completed through contacts M1, N1', M2, N2', M3, N2', M11, N11 to the source S either separately or simultaneously. Each of these sets of circuit closing contacts is associated with relays A, B, C, D, etc., there being a relay for actuating the contacts in each channel I, 2, 3, and N. Each of the relays A, B, C, etc. has an actuating winding I0 having one terminal connected to ground as shown. The other terminal of the winding of relay A is adapted to be connected through pre-select relay contacts I2 when closed to the negative terminal of a source of potential I4 having its positive terminal grounded. In a similar manner the free ends of the windings I0 of relays B, C to N are adapted to be connected through pre-select relay contacts I6, I8, etc., respectively when closed to the negative terminal of the source I4, connected with line 22 the positive terminal of which source is grounded.

Relay A has associated therewith a holding circuit including a pair of contacts 2U which are closed when the winding I 0 is energized and completes a holding circuit from 2U through the line 22 to the negative terminal of the source I4 and to ground and through the winding III so that after the winding III of relay A is first energized the holding circuit including the line 22 maintains A energized until said holding circuit is broken by means of master release key T connected in series with line 22 and source I4, and normally closed. In a like manner contacts 20, 24, 26, etc. associated with the holding circuits for relays B, C, etc., respectively, are closed after initial energization of the relay windings so that the windings remain energized until the holding circuits are interrupted by key T. Energization of windings A, B, C, or any one thereof, closes the circuits between channels I, 2, 3 etc. and the program source S via contacts M1, N1', M2, N2', etc. Each of the contacts I2, I8 and I8 respectively, is associated with relays A1, B1, C1, etc. respectively. These relays each have a winding 28 connected as shown with a master control circuit including a master combination set-up key 3D having one terminal grounded and the source I4 having its positive terminal grounded.

Each of the windings 28 on the relays A1, B1, C1, etc. have one terminal connected to the ungrounded terminal of the master combination set-up key 30. The other terminal of the winding 28 on relay A1 is connected with one element of a pre-selector switch A2. The other element of the pre-selector switch A2 is connected by line 34 to the negative terminal of source I4. In like manner the other terminals of windings 28 of relays A1, B1, C1, etc. are connected with an element of pre-select keys A2, B2, C2, as shown. Keys A2, B2, C2, etc. are locking type keys. All other keys used are instantaneous type keys or switches. Each of the pre-select keys A2, B2, C2 have an element connected, as shown to line 34 connected with the source I4. Indcating elements A2, B3, C3. etc. each have one terminal connected with an element in the preselector switches A2, B2, C2, etc., and the other terminal connected by Way of ground to the positive terminal of source I4.

In operation it will be assumed that none of the channels between source S and any utilization points is completed. It will be assumed further that it is desired to complete only channel I between the source S and the utilization point. This is accomplished by closing pre-selector switch A2 only. This closes the circuit through A2 to indicate which channel is being prepared for completion. At the moment it is desired to complete the circuit through A1, all that is necessary to do is to close the master combination L set-up key 38. This completes a circuit through the winding of relay A1. Relay winding 28 of A1, being energized closes the contacts I2 and completes the energizing circuit through the relay winding I0 of relay A. This relay actuates the contacts M1, N1 to complete a circuit between source S and channel I. Simultaneously holding key 20 is closed by relay A to complete a holding circuit through winding I0 of relay A.

Channel I will, therefore, remain connected to i S until this holding circuit through key 20 is interrupted irrespective of the interruption of the circuits at contacts I2 or A2.

Assuming that a few moments later it is desired to interrupt the circuit through channel number I and to complete a circuit through source S and a utilization point between channels 2 and 3. Pre-selector keys B2 and C2 are closed. When the time comes for making the change key T is opened, thereby breaking the holding circuit through winding Ill of relay A. Channel I is disconnected from S when the contacts M1, N1 are permitted to open. Master combination key 30 is now closed and, since pre-selector keys B2 and C2 were previously closed, windings 28 of relays B1, C1 become energized to close contacts I6 and I8 respectively. Closing of these contacts energizes the winding I0 on relays B and C. Relays B and C now complete the circuits between S and channels 2 and 3 by operating contacts M2, N2 and M3, N3, respectively. Simultaneously with this action relays B and C close contacts 24 and 26, respectively in the holding circuits for windings I0 of relays B and C thereby insuring that the circuits through channels 2 and 3 remain completed until the holding circuits through ID are broken. Interruption of these circuits and the connection of other circuits may be accomplished in a similar manner.

While the invention has been illustrated with reference to a single source and 3 channels for connecting said single source to any utilization point, it will be understood that the source may be connected over a greater number of channels or groups of channels. This may be accomplished by merely adding channels and contacts M11, N11 and operating relays similar to A, A1, A2, etc. for each channel added.

Likewise it will be understood that the present invention contemplates the application of applicants novel channel selector and completing circuit to a communication system comprising a plurality of program sources or studios S, S1, S2 etc. and a plurality of channels I, 2, 3 etc. one or more of which may be completed between one or more of said studios and a remote point. The circuit for accomplishing this involves the use of groups of relays A, A1, etc. for each source as described in detail in connection with Figure 1 there being a set of relays A, A1 etc. for each channel. These circuits need not be described in detail here. However, applicant has shown diagrammatically in Figure 2 a system in which a plurality of program sources or studios S, S1, S2, Ss, SN etc., are arranged to be completed by relays A, B, C, etc. and IA, IB-IC through one or more channels I, 2--N respectively with a rev mote point or points not shown. In this arrangement each studio S, S1, etc. to SN is equivalent to the studio S of Figure 1. Each contact C1, C2, C3 etc. and C1, Cz, Cs etc. indicates a channel completing contact involving a double line and each is equivalent to the contacts M1, N1 of Figure 1. Likewise each symbol A, B, etc. IA, IB, etc. represents an actuating or channel closing means including relays A, A1, B, B1, etc. of Figure l. The studios S, S1, etc. may be connected with one of the channels I, 2, 3, 4-N separately or with several channels simultaneously.

In operation here as in the arrangement of Figure 1 the pre-select keys associated with the channels it is desired to complete are set in advance. The indicators are energized to show which channels are to be closed. At the desired instant the master combination set up key 30 is closed. The windings through the relays associated with the selected channels are energized, the holding circuits are completed and the channel contacts closed and retained closed until the master release key is closed.

Having thus described my invention and the operation thereof, what I claim is:

1. A plurality of sources of electrical energy, a plurality of utilization points, and means for connecting one or more of said sources with any one or any number of said utilization points comprising a line connected with each of said sources, a channel connected with each of said utilization points, normally open contacts adapted when closed to connect each of said lines connected to said channels to said sources, a relay associated with each pair of contacts, an ener-A gizing circuit connected with each of said relays, said energizing circuits being normally open, a control circuit for said energizing circuits including pre-selector switches and energizing circuit closing means controlled thereby, there being pre-selector switches for each channel and a single master control circuit for connecting said pre-selector switches and energizing circuit ciosing means with a source of energy.

2. A plurality of sources of electrical energy, a plurality of utilization points, and means for connecting one or more of said sources with any one or any number of said utilization points comprising an incoming line connected with each of said sources, a plurality of outgoing channels connected with said utilization points, means for connecting one or more of said outgoing channels with one or more of said incoming lines including sets of normally open, contacts interposed between said outgoing channels and said incoming lines, a contact closing relay associated with each set of contacts, an energizing circuit Connected with each of said relays each energizing circuit including normally open contacts, a control circuit for including pre-selector switches and relays, there being a pre-selector switch and a relay for each channel, one of said last named relays being associated with each of the normally Y open contacts in said energizing circuit and a master control circuit for connecting said preselector switches and associated relays with a source of energy.

3. A plurality of sources of electrical energy, a plurality of utilization points, and means for connecting one or more of said sources with any one or several of said utilization points comprising, a control station at each source, a line connected between each of said sources and said control station at said source, a channel connected between each of said control stations and said utilization points, means for connecting each of said last named channels to one or more of said lines connected to said sources, said means including a normally open set of contacts between each of said last channels and each of said lines, a relay operatively associated with each set of contacts, an energizing circuit connected with each of said relays, said energizing circuits hav ing normally open contacts, a control circuit for said energizing circuits including pre-selector switches and circuit closing relays controlled thereby and adapted to close said normally open contacts in said energizing circuits, there being a pre-selector switch and a relay for each energizing circuit, a master control circuit having a master control key for connecting said pre-selector keys and associated relays with a source of energy, and a master release key common to all of said energizing circuits.

4. A plurality of sources of electrical energy, a plurality of utilization points, and means for connecting one or more of said sources with any one or a number of said utilization points comprising, a plurality of control stations, a line connected between each of said sources and one of said control stations, a channel connected between each of said control stations and said utilization points, circuits for connecting one or more of said channels to one or more of said lines, said circuits including normally open contacts, a relay connected with each group of said contacts, an energizing circuit connected with each of said relays, each circuit including normally open contacts, a control circuit for said energizing circuit including pre-selector switches and relays controlled thereby, there being a pre-selector switch and a relay for each of said last named normally open contacts, a source of potential connected with each of said energizing circuits, and a master control circuit for connecting said energizing circuits including said pre-selector keys and associated relays with said source of potential.

5. A device for controlling the connection of one or more of a plurality of program sources to one or more outgoing channels comprising a plurality of sets of automatic magnetic relays for interconnecting each of said sources with each of said channels, there being a set of relays for each program source, selecting means for preconditioning selected ones of said relays, and switching means common to all of said selecting means for rendering the selected ones thereof operative to actuate said relays.

6. In a broadcast distribution system, a pluyrality of sources of signals, a plurality of utilization points, a system for connecting one or more of said sources of signals to one or more 'lines leading to said utilization points and for controlling the connection of each source to said one or more lines from said sources comprising magnetic relays for interconnecting each source with each of said channels, there being `a separate relay for each channel and a set of relays for each source, energizing circuits including preselector switches connected with each of said aforesaid relays, and a master key for connecting each of said circuits to a source of potential whereby the relays associated with energizing circuits in which the preselector switches have been closed will be energized when said master key is closed.

7. In a broadcast distribution system, a plurality of sources of signals, a plurality of utilization points, a system for connecting one or `more of said sources of signals to one or more lines leading to said utilization points and for controlling the connection of each source to said one or more lines from said sources comprising magnetic relays for interconnecting each source With each of said channels, there being a separate relay for each channel and a set of relays for each source, energizing circuits for each of said aforesaid relays, said energizing circuits each including a preselector switch, a signalling device connected with each of said circuits and adapted to, be energized when said preselector switch is closed, and a master circuit connecting each of said energizing circuits including said preselector switches with a source of potential, there being a master control key in said last named circuit.

8. In a broadcast distribution system the combination of a source of signals, a plurality of outgoing tWo Wire channels, and means for connecting said source of signals to one or more of said channels comprising, lines connected with said source, pairs of normally open contacts, there being a pair for each outgoing channel, a connection between the contacts of each pair and said lines, a connection between the other contacts of each pair and a different one ofsaidchannels, a plurality of magnetic relays each having a winding and an armature operatively associated with the pairs of contacts, there being a magnetic relay for each pair of contacts, an energizing circuit for each of said windings each of said energizing windings including normally open contacts, a Contact closing relay associated with each of said sets o normally open contacts in said energizing circuits, an energizing circuit for each of said contact closing relays, said energizing circuits having a portion in common, a preselector switch in each of said last named energizing circuits, and a master key in said portion common to said energizing circuits.

9. A device for controlling the connection of one or more of a plurality of program sources to one or more outgoing channels comprising, a plurality of sets of automatic magnetic relays for interconnecting each of said sources with each of said channels there being an automatic relay for each channel and a group of automatic relays for each program source, a relay and a preselector switch connected With each of said automatic relays, said switches being in an energizing circuit common to all of said last named relays, and a master control switch in said energizing circuit.

CHESTER A. RACKEY. 

